The present invention relates to the field of uterine monitoring for veterinary purposes and, more particularly, to such monitoring using electronic devices.
All mammals that deliver live offspring carry their fetus inside a uterus. As it grows and stretches to accommodate the fetus, the uterus periodically contracts. Studies of human pregnancies have shown that the frequency of these contractions will increase 24 to 48 hours prior to labor and delivery. Labor occurs when regular contractions dilate the cervix, the opening to the uterus, to allow delivery of the offspring through the birth canal.
The use of electronic devices to monitor human labor and delivery has been popular since the 1970's. Obstetricians often monitor the uterine activity of women to predict the onset of labor, both term and preterm, to ensure that proper precautions are initiated. Home monitoring of uterine activity has become increasingly popular, and is now advocated by many obstetricians and perinatologists.
Uterine monitoring uses a tocodynamometer to sense uterine irritability (a low amplitude, high frequency pattern) and uterine contractions. The tocodynamometer is placed outside a woman's body near the uterus.
In the 1980's, the design of the tocodynamometer improved sufficiently to allow patients at risk of preterm delivery to have their uterine activity monitored at home. The current home monitoring devices are much more sensitive to the detection of uterine activity than prior equipment used in a clinical setting to monitor term gestation. In fact, monitoring devices can now detect uterine activity as early as sixteen weeks into gestation.
For the most part, uterine monitoring has been limited to humans. One reason may be that delivery of human offspring takes so much longer delivery of other mammal offspring. For example, a typical human delivery averages twelve to fourteen hours from the onset of labor. A cow, on the other hand, calves in around three hours.
Veterinarians, animal owners, and other animal health care providers could benefit from monitoring uterine activity in animals to permit timely response, management, and treatment of animals during gestation, labor and delivery. The ability to herald the onset of labor before the animal exhibits the typical signs allows quicker response and preparedness on the part of the owner, caretaker, or veterinarian. Such uterine monitoring can be especially beneficial for animals in the growing speciality of planned animal reproduction because certain artificial inseminations are sufficiently valuable to warrant close evaluation of the subsequent pregnancy and general prenatal health of the animal.
There are many other conditions which threaten the viability of the mammal offspring that may benefit from uterine monitoring. These conditions include inducing or augmenting labor, multiple gestation, reproductive/infectious disease, a history of premature delivery of the offspring, uterine or pelvic abnormality.